Insulation Calculator — Rolls & Batts Needed
Spec no. 12How to use
Enter the total area to insulate in square feet (wall area = 2 × (length + width) × height for a room; for an attic use length × width of the ceiling). Enter the coverage per bundle or roll from the package (R-13 batts commonly cover ~40-47 sq ft per bag). The calculator adds 5% waste for cutting and fitting.